#include "stdafx.h"
#include<iostream>
using namespace std;
//求100!
double jiec(int a)
{
	double s=1;
	for(int i=1;i<a+1;i++){
		s=s*i;
	}
	return s;
}
int main()
{
	double a=100;
	double s;
	s=jiec(a);
	cout<<s<<endl;
}